Opuntia wilcoxii sp nov

A tall, bushy plant, 1 to 2 meters high, very much branched; joints oblong, thinnish, large,

2 cm. long, dark green, more or less purplish about the large areoles, finely puberulent; glochids numerous, long, yellow; spines 1 to 3, one very long (5 to 6 cm. long), porrect, white or somewhat yellowish; flower, including ovary, 6 cm. long, yellow; petals oblong, mucronate; ovary bearing few large areoles, these filled with brown wool and yellow glochids; filaments short; style thick, 2 cm. long, with 10 stigma-lobes; fruit pubescent, 4 cm. long.

Very common on the hills in the coastal plain of western Mexico from southern Sonora to southern Sinaloa, Mexico, where it was frequently collected by Rose, Standley, and Russell in 1910; their No. 13546, with flower, from Fuerte, Sinaloa, is selected as the type of the species. It is named for Dr. Glover B. Wilcox, who first sent in living specimens in 1909.

Figure 211 represents a joint of the type specimen.

To this series belong two plants which we have not been able to identify but are here briefly characterized:

The first, a very peculiar species, collected by Rose, Standley, and Russell, March 14, 1910 (No. 12853), on the dry hills near Alamos, Sonora, Mexico, is unlike any of the described species. It is living both in Washington and New York, but it has not done well in cultivation. It may be described as follows:

Bushy; joints oblong, thickish, pale green in color, with very short puberulence, nearly or quite spineless; glochids yellowish or greenish, numerous; young areoles brown in the center, white-woolly in the margin; flowers and fruit not known.

Dr. H. H. Rusby collected the second species on the Balsas River, southern Mexico. It comes from the region of O. velutina, but we do not know its flowers. It may be described as follows:

Joints oblong, 18 cm. long, but cultivated specimens smaller, usually obovate, dark green; spines few, short, at first white; young areoles large, bordered with white wool, bearing the spines and glochids from the center.

Living specimens are growing in the New York Botanical Garden under No. 32811.

Series 17. TOMENTOSAE.

Tall, erect, pubescent or puberulent species, with flat persistent joints, the spines, when present, white. We know three species, natives of Mexico and Guatemala.

Fig. 211.—Opuntia wilcoxii. X0.4.
M. E. Eaton del

1. Upper part of flowering joint of Opuntia leptocarpa. 3. Flowering joint of Opuntia velutina.

2. Fruit of the same. 4. Upper part of joint of Opuntia megacantha.

(All natural size.)

Continue reading here: Key to Species

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